Finding the Fourth Proportional to 28,308.40, 42,462.70 and 8,587.12

Step by Step Solution

1. Step 1: Write the proportion equation
   28,308.40 : 42,462.70 = 8,587.12 : x
2. Step 2: Convert to fraction form
   28,308.40/42,462.70 = 8,587.12/x
3. Step 3: Cross multiply
   28,308.40x = 42,462.70 × 8,587.12
4. Step 4: Simplify right side
   28,308.40x = 364,632,300.42
5. Step 5: Solve for x
   x = 364,632,300.42/28,308.40
6. Step 6: Final answer
   x = 12,880.71